Benjamin ceawford



BENJAMIN CRAWFORD, OF PITTSBURG, PEN N SYLVAN IA.

Lam Paten; No. 76,607, ma Afm-z 14,1863.

IMPROVEMENT IN STEAM-GENERATOR.

@the .tttule referat tu in that tstttrt atmtmrt'mtting tart tf the sans,

TO .ALL WHOM I'l MAY CONCERNg l Be it known that I', BENJAMIN CRAWFORD, of the eity of`Pittsburg, in the county of Allegheny,and State oi' Pennsylvania, have invented a new and useful Improvement in Steam-Boilers; and I do hereby declare the following to bea full, clear, andexactdescription thereof;

In the boilers of steamboats plying our western waters, floats are placed to ioat on the surface vof the water, and thus indicate to the engineer, by a gauge or index onthe outside ofthe boiler, the height of the Water within. This is necessary as a precaution against the water in the boiler becoming too low, with a. consequent danger-of explosion. Two or more boilers are likewise commonly placed oneach boat, and connected together by pipes leading from each to a common mud-drum. It has been found that under the almost constant motion to which the-loatsare liable from the ebullition of the water, its rising and falling, with an increase or decrease in the supply of feed-water, and its flow andrelow with the varying motions of the boat, the oats are liable to and sometimes do become-loosened-from the -stems which carry them, and as they are made ofv light material, and commonly of small` size, the force of the steam rushing out through the steam-pipe or throttle notunt'requently carries the loosened float into or againstthe mouth of the steam-pipe, and of course..prevents the escape of steam therefrom. The inevitable result is, that as the formation of steam in-the boiler thus closed is not prevented, the pressure of the steam so formed and confined in the top ofthe boiler forces the water contained in the closed boiler out into the other boxlers'through the mud-drum and the pipes leading thereto. The surface of the water in the-closed boiler is thus brought below the re-line, with the usual resultslof an undue heating' of the boiler, a serious lessening of the tenacity of the metal composing it, explosion, destruction of property, and almost invariably a .loss ,of life. Usually, in such cases,A the causes of the explosion `are unknown. The

gauge of the exploded boiler having been inoperative, the engineer has not been previously warned, With they explosion the ioat usually disappears, and nothing remains to show the cause of the disaster..

V'lhe object of my invention is to prevent explosions so caused by rendering it impossible for the iioat, when loosened, to close the'steam-pipe, and the nature of it consists in protecting the mouth of the steam-pipe by one' or more bars,la grating, or a perforated plate, covering it, or bye-number of projections arranged around and near to it, or by so branching .or dividing it that thesteam may enter it at two or more points. The'oat will then be prevented from entering it, or closing it, or obstructing all the passagesl leading thereto.

To enable others skilled in the art to make and use my invention, I will proceed to describe-its construction and inode of operation, referring'for thatl purpose to the accompanying drawing making a part. of this fspecli.A rcation, in which-- l Figure 1 is a. perspective view of a'pair of fined boilers, so much of onc-oi` the boilers being cut away as is necessary to show my improvement placed therein and Figure 2 is a sectional view, formed by planes passing vertically thronghthetsteamdrnm,.steam-pipes, boilers, and mud-drum, and horizontally just beneath the boilersn' 1 Like letters of reference indicate similar parts in each.

a a aretwo cylindrical-dried boilers, resting'on and bedded in the furnace-wa1ls, l1. c c are the furnacedoors, d d the ues, e the mud-drum, ff the pipes connecting the mud-drum e and boilers a; g g the steampipes leading to the steam-drum la, and/t' the dont, attached toa stem, i', which, by a gauge or index of the usual construction, on'the outside of the boilerA a, indicates the height of the water-within. Asl the' Iioat z plays up and down on the surface of the moving and boiling water, it sometimes becomes loosened, and, being of light material, is carried by the force oi' the rushing steam into the mouth of the pipe g, closing it partially or wholly, with thedisastrous results above set forth. To prevent this, Iprotect the mouthof the pipe g in any of the ways above mentioned, but, as shown vin the drawing, I cover it with a plate, m, of any desirable length, andlhaving perforations, n, in any desirable number If, then, the float z be carried up against the plate m, so l-as tovclose a part of the. perforations a, a suicient number will still be open to allow the free escape of steam. Hence the gauges, ifl there be any in -the other boilers, will indicate correctly the height of the water in all, and if dition, carrying with it a consider ater will be deferred till` the engineer will observe,

there be none the possibility of `explosion from a lack of w as well as in a if he be at all attentive, the non-working'ot the gauge. Thus it is usetul in a single boiler, gang of boilers. A

My invention possesses another advantage, of a somewhat different character. In the steam-boiler, as ordinarily constructed, the formation of steam is most rapid immediately under the mouth of the pipe,g,and from that point the steam rushes into the pipe g with great rapidity, and passesotl' in a highly-saturated conable quantityof hot Water.` The heat contained in the water thus-carried oit is of course lost, with the force which it represents. A By placing over the meut-h ofthe pipe g a long perforated plate, m, this evil is electually obviated. The steam which then escapes into the pipe g is gathered from the" whole or the greater part of the surface of theV water in the boiler, 'and necessarily passes oil' ina drierstate, whereby its expansive force is considerably increased. The same end may be secured by substituting a fine grating for the plate m.

For the purpose of preventing the stoppage of the pipe g by the ioat t', when the latter becomes loosened from its stem z", I sometimes substitute for the plate m one.or more hars, or a grating, or arrange a number of projections around the mouth of the pipe g, pointing downwards, or divide the boiler end of the pipe g into branches, two or more, so that thesteam will enter it at different points In this mannerA entirely obviate all danger of the explosion of boilers from the loosening of the float.

The consequent benefit of saving of property and life is obvious.

Having thus described my improvement, what I claim as m Patent, is-

The arrangement of a perforated plate m over the mouth of the steam-pipe g, inside ot' the boiler, in combinatonwith the pipe g, for the purposes hereinbefore described.

In testimony whereof, I, the said BENJAMIN CRAWFORD, have hereunto set my hand. l v

BENJ. CBAWFORD y invention, and desire to securcby Letters Witnesses:

Gao. H. CHRISTY, A. S. NICHOLSON; 

